This paper describes a Piagetian-based evaluation measure and results obtained from the use of this measure with 1260 pre-kindergarten inner-city children. The children were enrolled in a program designed to develop their readiness skills. Family income, limited educational opportunities of adult members of the family, and dependency on public assistance were determinants of qualification for the program. The Pupil Evaluation Measure (PEM) was based on program objectives expressed in Piagetian terms. Each of nine tasks was designed to measure progress towards a more abstract level of cognitive development. Teacher assistants administered PEM to each child 5 times during the school year. Comparisons between October and June test results showed an increase in the proportion of students performing above the semiconcrete/semiabstract level on all nine PEM tasks. Appendices include graphs of PEM scores from the entire year, average pre- and post-test scores on the Stanford-Binet Intelligence Tests given the children, and procedures for administering and scoring the PEM. (BRT)